[Note: The statements below are intended solely to stimulate discussion among the Expert community, and do not represent the position of OurEnergyPolicy.org. Text in italics indicates clarification or expansion.]
The majority of the recommended policies in this document are based on known technologies or known technology development directions. However, human ingenuity will definitely produce additional solutions (e.g., compressed air engines). The policy should remain open to embrace new technologies as they become viable. It is critical to follow technological innovation and once one matures, it should receive an even playing field with other alternatives.
The New York Times had a story about increasing interest in gas-to-liquids conversion. Interest is driven by the growing spread between natural gas and crude, in terms of cost per BTU. They cite high capital cost of GTL plants as the the chief inhibitor, but don’t give specific numbers. Story at
http://www.nytimes.com/2010/12/24/business/energy-environment/24fuel.html?src=busln.
This next one was published a few days ago (12/20) at Green Car Congress, based on a press release from Oxford Catalysts Group plus conference presentation at the end of October. (The link is http://www.greencarcongress.com/2010/12/oxford-20101220.html ). It reports that Oxford Catalysts Group has received its first order for a full-scale commercial Fischer-Tropsch microchannel reactor for synthetic fuel production. “Full-scale commercial” may be stretching a bit; it’s for a 25 bpd biomass-to-liquids demonstration plant at Gussing, Austria.
Microchannel reactors are, in my opinion, one of the really promising technologies for our energy future. They promise higher efficiency and higher productivity than the big reactors in traditional chemical plants. Equally or more important is that they are practical for small-scale operations. They can be mass-produced in factories, and don’t require huge plant sizes to achieve “economies of scale”. So it’s realistic to project thousands of small plants sprinkled around, operating close to the carbon source being used to make the synthesis gas for the reactor. It should make for an economical way to capture stranded natural gas, or to make localized fuel synthesis from biomass practical. But it’s been slow to develop. Not sure why.
One thing that bothers me about most everything I’ve read lately about gas / coal / biomass – to – liquids projects (GTL / CTL / BTL) is that they most all seem focused on using the gas / coal / or biomass as both a carbon source and as an energy source to drive the production of synthesis gas. That means that they release a lot of CO2 (over and above what will be released when the fuel is burned) and yield only about half as much (very roughly) in fuel as they could if they were driven by external energy. High temperatures are needed, so the non-carbon choices are concentrated solar, high temperature nuclear, or electricity. The last is wasteful of energy, but can be appropriate when one has a stranded source.
Anyway, I find it curious that nobody seems to be talking much about that option. It could be implemented immediately; no R&D breakthrough required.
Let me just note that that others have identified the same problem you have pointed to, specifically, that using coal as both a heat source and a feedstock to make liquid fuel produces large amounts of CO2 and makes poor use of a limited resource (coal). Different approaches have been suggested to deal with this. One approach is to be found in the National Academy of Science’s “ America’s Energy Future” where they propose carbon capture and storage (CCS) to deal with the CO2 issue. I’m not a fan of CCS and would not suggest holding a large part of our liquid fuel energy future captive to that unproven technology. Further, the NAS approach burns up too much coal and would much more rapidly deplete one of our remaining resources (Some analysts claim that we have far less usable coal than is presently estimated).
Other alternatives seem to come down to using biomass as the heat source, concentrated solar, and high temperature nuclear plants. Biomass is a poor choice in my view if it means that less ethanol would be produced. Concentrated solar seems to be too limited. First, the best places for concentrated solar are in the desert areas of the southwest, which are far from the coal fields. Second, the most economical way to run any production process is to have a high utilization factor. This is a challenge for concentrated solar, not only because of diurnal effects, but also seasonal ones. Data taken at the Desert Rock, Nevada monitoring station, not too far from the concentrated solar facilities in California, show that the solar insolation in the winter is about half that of the peak summer values. In order to run continuously under such daily and seasonal variations in the solar input, it seems that one would need to build a vast energy storage system and that has its own price. One might, however, just make liquid fuels in the desert during the peak months and then distribute this product over the whole year, according to the demand. If the making of the liquid fuel requires water, how does one do this in the desert? People are playing with the idea of using the desert areas of North Africa to produce electricity/ liquid fuels and shipping these products to Europe. Perhaps the folks promoting this idea have figured out what to do about scarce water and the variability of solar insolation. I haven’t kept up with the status of this concept and if I lived in Europe I would be quite uncomfortable in establishing a solar based equivalent of OPEC. There is much to commend energy independence.
This leaves nuclear. There are a variety of possible nuclear pathways from high temperature plants that use helium as the coolant (HTGRs), to high temperature molten salt reactors, to liquid metal reactors. High temperature plants have the additional potential benefit of using air as the ultimate heat sink, therefore making it possible to locate them close to the coal sources. In a water constrained world, the ability to use air as the ultimate heat sink is a big plus.
None of these nuclear possibilities are implementable in the short term. We can’t even get the nation to open a nuclear waste repository (Yucca Mountain) although the science supports this and the NRC has an outdated regulatory review process for light water reactors. Their own research out at Sandia labs (The SOARCA program) shows that even if everything fails in a highly unlikely core melt accident, the internals within the reactor vessel and those within the containment building- while it remains intact- act as a large, complex, passive filter for radioactive material. I say passive because these very small release rates to the environment would occur without any mitigative operator actions and without any active engineered safety feature working. Such small releases would be highly delayed, some longer than 24 hours, giving ample time to implement emergency planning efforts, like sheltering. These significant source term reductions are the result of natural chemical and physical processes. If light water reactors are “inherently safe” based on NRC research, why does it take so long to get an LWR license for a new plant? Why do some people support the science of global warming and not the science of securing nuclear wastes in an underground repository, and vice-versa?